Don't buy a Signal Generator Without Considering These 6 Things!Follow article
Buying a new signal generator can be a pretty significant investment for your lab. Before zeroing in on the perfect model, there are a few items (6 to be exact) that you should consider. Without further ado...
6 Things to Consider Before Buying a Great Signal Generator.
1. Waveforms and modulations
It should go without saying, but it's critical to consider the types of waveforms that could be produced with the signal generator. Almost all signal generators will be able to produce very common waveforms such as square waves, sine waves, triangle, sawtooth, etc. More advanced waveform generators can produce arbitrary signals that are complex like analogue and digitally modulated signals that can simulate RF waveforms or modulation schemes like those used in modern SDRs or software-defined radios
2. Frequency Limits
Single generators are used to test the response of a circuit to an analogue voltage input. Depending on the circuits to be tested or the signals that must be applied as an input to the device under test, the frequency range of the signal generator must be considered. With the maturation of high-speed ADC and DACs and the crowding of lower frequency RF spectrum, circuits are continually pushing to higher and higher frequencies. Make sure to pick a signal generator that has a usable frequency range to cover current and future test needs.
Another important consideration is precision of the signal generator's output, which is usually described as resolution. Since most signal generators convert digital signals into analogue voltages, the resolution of the DAC (Digital to Analog Converter) becomes a critical specification of the waveform generators ability to recreate the designed signal. If you need high resolution, look for signal generators with many bits of resolution on their DAC.
4. Sampling rate
According to the Nyquist Sampling Theorem, any signal sampled at twice as fast as its highest frequency component can be perfectly reconstructed. For this reason, the sampling rate as well as the frequency range are both important considerations when picking a great signal generator.
5. Output Impedance
Another important consideration when buying a signal generator is its ability to drive a load at its output. This max load is determined as a function of output impedance measured in ohms. It is important that the load impedance matches the output impedance. Most signal generators have an output impedance of 50 ohms, which is common for most RF signal chain components.
6. Phase Lock Capability
Many RF systems require various signals to be phase-locked for synchronization. The most common is to phase lock to a common LO or local oscillator or clock. If this is a need for the circuits you will be testing it is important that your signal generator includes this ability to input external signals for phase locking.
Looking for Signal Generator Recommendations?
We've compiled a list of 5 great signal generators for any budget on the FromDC2Daylight.com website.